Cassini spacecraft to end its mission tomorrow with a 70,000mph death plunge into Saturn’s atmosphere

Nasa scientists are preparing to kill off the Cassini space probe with a spectacular suicidal dive into Saturn’s atmosphere on Friday.

The 22ft robot craft will break into fragments and burn up as it ploughs into the ringed planet’s cloud tops, ending a 20-year mission that cost £2.9 billion.

Cassini was launched in 1997 and took seven years to travel two billion miles to Saturn, before embarking on a 13-year journey of discovery that delivered a wealth of scientific data on the planet and its moons.

The north pole of Saturn’s icy moon Enceladus is seen in an image from the Cassini spacecraft on 14 October 2015Credit: NASA

Now with the spacecraft running out of fuel, and soon to become impossible to steer, controllers have chosen to bring the mission to a fiery end.

Scientists expect to lose contact with the probe at around 12.55pm UK time as Cassini begins to feel the effects of drag from Saturn’s atmosphere and starts to tumble, causing its dish antenna to lose sight of Earth.

At this point the craft will be roughly 930 miles above the planet’s cloud tops. From then on, Cassini will start to burn like a meteor and tear apart. Within two minutes of signal loss the probe will be completely consumed.

In brief | Nasa’s Cassini mission

During the dive Cassini will be travelling at around 70,000mph. Its plunge to destruction will mark the end of a series of 22 daring orbits that allowed the probe to slip between Saturn and its rings.

Because Saturn is so far away, the spacecraft’s last gasp transmissions will take 83 minutes to reach Earth.

Earl Maize, Cassini project manager at Nasa’s Jet Propulsion Laboratory in Pasadena, California, said: “The spacecraft’s final signal will be like an echo. It will radiate across the solar system for nearly an hour and a half after Cassini itself has gone.

“Even though we’ll know that, at Saturn, Cassini has already met its fate, its mission isn’t truly over for us on Earth as long as we’re still receiving its signal.”

Cassini: Getting to Saturn

Right up until it beams its final signals to Earth eight of the spacecraft’s 12 scientific instruments will be gathering data from the top of Saturn’s atmosphere and transmitting information about its structure and composition.

Cassini’s cameras will capture their final images of looming Saturn and its moons several hours earlier. They will be radioed to Nasa’s Deep Space Network antenna complex in Canberra, Australia, before being posted on the mission website.